As a bookbinding apparatus that binds a book by wrapping a bundle of sheets with a cover, there has been an apparatus wherein the back of a bundle of sheets and a cover are pasted together with a liquid state adhesive or an adhesive tape. For example, Unexamined Japanese Patent Application Publication No. H09-156249 discloses a means wherein the side edges of the bundle of sheets are lined up on a table, the bundle of sheets thus lined up is clamped at a sheet fixing portion, and the bundle of sheets thus clamped at a sheet fixing portion is caused by a sheet fixed portion moving means to reciprocate between a paste spreading roller that spreads paste on the back of the bundle of sheets and a dryer portion that dries the pasted portion forcibly. Further, Unexamined Japanese Patent Application Publication No. 2004-351726 discloses a means wherein adhesives are sufficiently solidified by measuring ambient temperature after coating adhesives on the back and thereby controlling interposing time for clamping.
However, in the apparatus that binds a book by wrapping a bundle of sheets with a cover, when bookbinding is performed by wrapping a bundle of sheets with a cover, if the bundle of sheets is sandwiched in a wavy form, there has been a problem that corners of the spine do not become straight lines and the spine does not become flat, even conducting folding formation (back corner forming) of the spine by pressing a cover against the bundle of sheets.
Means to solve the aforesaid problems is not described in any of the aforesaid Nos. H09-156249 or 2004-351726.